Extrusion apparatus



Jan. 19, 1932; w, A. BENZ 1,841,396

EXTRUSION APPARATUS Filed Feb. 13. 1931 a sheets-Sheet 1 Z6 24 as 11 22 if' ,2. J LL26 59 INVENTOR 4 Jan. 19, 1932. w. A. BENZ 1,841,396

EXTRUSION APPARATUS Filed Feb. 13. 1931 s Sheets-Sheet 2 INVENTOR EXTRUS I 0N APPARATUS Filed Feb. 13. 1931 3 Sheets-Sheet 3 INVENTOR Patented Jan. 19, 1932 UNITED STATES PATENT OFFICE WILLIAM A. BENZ, OF PARNASSUS, PENNSYLVANIA, ASSIGNOR TO ALUMINUM COM- PANY OF AMERICA, OF PITTSBURGH, PENNSYLVANIA, A CORPORATION OF PENNSYL- VANIA EX'IRUSION APPARATUS Application filed February 13, 1931. Serial No. 515,505.

the mandrel is rigidly attached to the pres-.

sure applying means. In both cases, a suitable pressure ram is brought into a posltion to exert pressure on the billet and mandrel to perform the extrusion operation. Various modifications of these two mandrel arrangements make up, for the most art, the extrusion apparatus which are universally used.

In the extrusion of articles from hollow billets as, for example, in the extrusion of aluminum, it is essential to so control the extrusion operation that a portion of the billet remains in the billet cylinder. This unextruded metal is commonly referred to as the heel of the billet and consists primarily of dross which collects and solidifies on the top of the billet during the casting operation. To completely extrude a billet would entail the extrusion of the heel, thereby producing an inferior product. In view of the fact that the extruded productis formed with this heel of unextruded metal of inferior quality attached thereto, provision must be made for removing this unextruded material before the article can be removed from the die.

It is an object of this invention to provide a simple, inexpensive, effective, and durable apparatus for extrusion which will allow a quick and simple removal of the'heel from the extruded product. I r

Other and further objects will be apparent upon a consideration of the following de- 50 scription and the accompanying drawings which illustrate a preferred embodiment of my invention.

In the drawings Fig. 1 represents a sectional elevation through the tool assembly and billet cylinder pf arr-extrusion press; v

Flg. 2 represents a partial sectional elevation of an extrusion mechanism embodymg the principles of my invention;

Fig. 3 represents a view similar to Fig. 2, the cooperating mechanism being shown in a different position;

Fig. 4 represents a front elevation as viewed from the left of Fig. 2, part of the mechanism not being shown;

Fig. 5 represents, to an enlarged scale, an end view of the pressure block or ram nose;

Fig. 6 represents, to an enlarged scale, a sectional elevation taken on the line VI-VI of Fig. 5;

Fig. 7 represents, to an enlarged scale, a longitudinal view of the preferred form of mandrel or core;

Fig. 8 represents in side elevation the preferred form of mandrel locking plug;

Fig. 9 represents a view of the lug shown n Fig. 8 as viewed from the rig t.

Referring to the drawings, in which like reference numerals represent similar parts, Fig. 1 represents a type of extrusion apparatus well known to those familiar to the art. In this apparatus as shown, 10 represents a billet cylinder into which the billet 11 is placed through the opening at the right of cylinder 10 when the pressure applying ram or plunger 12 with its attached ressure block 13 is withdrawn therefrom. posed in front of and axially aligned with the billet cylinder 10 is the tool asembly. comprising a die 14 and aback-up ring 15 located in the bore of a suitable die ring 1o. A

retaining rin 17 held by cap screws to the face of he die ring 16 completesithejtool assembly and holds the 'variousele exits in coordinated relationship. The tool assembly is supported andguided into axial alignment with the billet cylinder 10by meansof the cavity bore 19in a suitable housing 18 adjacent to the cylinder" 10. A locking plate 20, operating; in a slot 21 the housing '18,

holds the tool assembly against the face of the cylinder 10, and is capable of movement out of locking position to permit the advancement of the tool assembly away from the face of the cylinder 10 on completion of the extrusion operation.

In operation, the billet 11, which is provided with a central cavity 22, is placed in the billet cylinder 10, the head or top of the hollow billet facing the ram nose 13. The mandrel 23, which is a loose, unattached, full floating piece is inserted in the central cavity in the billet and a suitable pressure applying means is actuated to bring the ram 12 into position to exert a pressure upon the end of the mandrel 23 forcin its flared end 24 into the billet and extrudlng the billet between the die 14 and the centrally disposed mandrel to produce a tubular member 25. In carrying out this operation, it is a usual practice to preheat the billet and mandrel to expedite the extrusion operation, the billet and mandrel being heated to approximately the same temperature to avoid any alloying effect and also to eliminate adhesion between the core and the material being extruded.

On completion of the extrusion operation, a portion of the billet, herein referred to as the heel, remains in the cylinder 10, and the mandrel 23 is imbedded in this heel and also extends an appreciable distance through the die 14. To remove the tube from the die, and also to recover the mandrel, it is necessary to cut the tube at some distance from the die and then hammer, or otherwise force the mandrel out of the heel, before the apparatus can be employed for a subsequent extruding operation. This procedure is disadvanta-.

geous as considerable time is consumed in removing the core and the extrusion mechanism is not, therefore, operated to its highest capacity.

In the preferred embodiment of my invention, shown in Figs. 2 to 9, only those elements of the mechanism which differ in construction from the apparatus shown in Fig. 1 have been designated by a new set of numerals.

In this form of apparatus, the mandrel 26, the general shape of which is similar to mandrel 23, is provided at its flared end with a tapped hole 27. This mandrel is shown to best advantage in Fig. 7. A locking plug 29 in the form a T, and provided with a thread 30 on a portion of its shank, is screwed into the tapped hole 27 in the mandrel 26. The pressure block 31, which is connected to the ra n 12 through the coupling member 32, is provided with a cylindrical cavity 33 and a passage or channel 34 shown to best advantage in the enlarged Figs. 5 and 6. To connect the mandrel to the pressure block 31, it is only necessary to insert the head of the T plug 29 through the channel 34, and twist the mandrel through a part-turn such as an angle of 90 degrees, thus detachably and movably securing it to the pressure block.

A connection of this nature, of which the one above described is a preferred type, is easily detachable, thus allowing rapid and eflicient handling of the mandrel when it is, as in the usual operation, removed at intervals and reheated in a suitable furnace. Moreover, the mandrel, while sufliciently secured to the pressure block to insure its ready removal from thedie after the extrusion operation, is, nevertheless, movably, secured thereto and retains a semi-floating character permitting of appreciable movement of the mandrel Into and out of axial alignment with the pressure block.

The tool assembly, hereinabove mentioned, is, in accordance with my invention, positioned for movement into and away from the housing 45. This movement may be accomplished by use of a pressure piston and cylinder mechanism such as shown in Fig. 2 and comprising a cylinder 35 and piston 36, the shouldered connecting rod 37 of which is connected to a bracket 38 bolted or otherwise attached to the retaining ring 17, the cavity 44 having been provided in the housing 45 to accommodate the bracket 38.

In the operation of this preferred form of mechanism, with the locking plate 20 in its locking position, the heated billet 11 is placed in the cylinder 10 as previously described in connection with Fig. 1. The mandrel 26, with its attached plug 29, is also heated to its desired temperature and is placed in locking arrangement with the pressure block 31, and the pressure applying ram 12 is operated to advance the mandrel through the central cavity in the billet.

A billet having been extruded into a length of tubing, the ram 12 is retracted from the billet cylinder, which action withdraws the mandrel 26, leaving the heel 39 of metal attached to the tube 25, projecting through the tool assembly. The mandrel is removed by simply twisting it through 90 degrees and is then immersed in oil and ready for replacement for a subsequent extrusion operation. The locking plate 20 is then raised in its slot 21, and by pro er manipulation of the three-way valve 40 uid pressure is admitted from the main 41 through pipe 42 into cylinder 35 to force the piston 36 with its attached piston rod 37 towards the left, thereby moving the tool assembly, together with its extruded tube and billet heel, forwardly and away from the billet cylinder 10 into a position under a shear blade 46, as shown in Fig. 3, by means of which shear the heel is readily severed from the tube 25 and the tube removed from the die. The tool assembly is now returned to position for a subsequent extrusion operation by proper manipulation of the valve 40 to admit fluid pressure from the main 41 through pipe 43.

It will be understood that the above-described arrangement of the detachably and movably secured mandrel and the movable tool assembly is susceptible of application, in suitable form, to any type of extrusion apparatus, and the specific terms used here"- inabove do not limit the invention set forth in the appended claims.

I claim:

1. In an extrusion apparatus, pressure applying means and a mandrel cooperating therewith; the said mandrel beingprovided with a part-turn connecting means whereby it may be detachably secured to the said pressure applying means and rendered semi- I floating with respect thereto.

2. In an extrusion apparatus, pressure applying means and a mandrel cooperatin therewith; the said mandrel being provide with a part-turn connecting means whereby it may be detachably and movably secured to the said pressure applying means, thereby permitting appreciable movement of the said mandrel into and out of axial alignment with thepressure applying means.

3. In an extrusion apparatus, pressure applyingmeansandamandrelcooperatingtherewith; said mandrel being provided with a part-turn connecting means and-said ressure .applying means being provided with a cavity in which the said member is detachably and movably secured.

4. In an extrusion apparatus, a billet chamber, a movable tool assembly cooperative therewith, pressure applying means, a mandrel detachably and movably secured to said pressure applying means and cooperative with said tool assembly, and means for moving the tool assembly up to and away from said billet chamber.

5. In an extrusion apparatus, a pressure applying ram having a ram nose associated therewith, said ram nose being provided with a central internal cavity, a channel communi- 4 eating with said internal cavity, and a mandrel provided with a coupling element of T form for introduction through said channel into said cavity, whereby the mandrel is detachably and movably connected with the ram 11056.

WILLIAM A. BENZ. 

